In the electro-erosive wire cutting of a workpiece, a continuous wirelike, thread-shaped or similarly elongated electrode of a greater length is transported axially from a feeding side of a workpiece to a receiving side through a cutting area on a workpiece, which cutting area is flushed with a working fluid of a dielectric nature or an electrolyte of a suitable conductivity.
An electric working current flows between the continuous wire electrode and the workpiece through a small work gap formed therebetween.
A wire made of an electrically conducting material, for example of copper, brass, steel, molybdenum, Wolfram or another metal or metal alloy or also so-called wrapped wires with a core and with layers of metal and metal alloys with a low volatilization temperature contained thereon, is used as a continuous elongated electrode for technical manufacturing reasons. These materials meet only in a limited manner the requirements which are made on the electrode during an electro-erosive wire cutting operation.
The electric discharge energy volatilizes not only the workpiece material, which is a requirement, but also, to a significant degree, the material of the continuous electrode, which results in inconsistent dimensions along the length of the wire.